The invention relates to an apparatus for heart examination by means of ultrasound waves generated by piezo-electric crystals, wherein the dimensions of the heart are derived from the times at which the crystals receive the echo signals reflected by the heart structure.
Dutch Patent application Ser. No. 6804410, laid open to public inspection, discloses an apparatus of this kind, wherein a catheter carrying on its end two piezo-electric crystals with opposite directions of radiation is introduced into the heart of a patient.
The fact that the known apparatus involves the introduction of a catheter into the heart constitutes, in practice, a considerable disadvantage, because it restricts the use of the apparatus to clinical application. A further disadvantage is the limited character of the information obtained, since only two points on a straight line are observed.